Changelog for Elixir v1.21

v1.21.0-dev

1. Enhancements

EEx

• [EEx] Support splitting middle expressions across EEx clauses

Elixir

• [Access] Add support for keyword lists in Access.key/2 and Access.key!/1
• [Code] Add :purge and :purge_all compilation tracer events
• [Code] Add support for the :erlc_options compiler option
• [Code.Formatter] Add a :migrate_atom_interpolations option
• [File] Accept an open IO device in File.stat/2, File.stat!/2, File.regular?/2, File.dir?/2, and File.exists?/2
• [IO.ANSI] Add bold/0, bold_off/0, dim/0, dim_off/0, blink/0, invisible/0, invisible_off/0, strikethrough/0, strikethrough_off/0, italic_off/0, underline_off/0, overline/0, overline_off/0, cursor_forward/0, cursor_backward/0, and cursor_home/0, aligning names with Erlang/OTP
• [Kernel] Improve performance of type constructors and complex intersections
• [Kernel] Warn on aliases that are never used because a later alias shadows them
• [Kernel] Warn on binary patterns with segments that are not byte-aligned
• [Kernel.ParallelCompiler] Add a hint when spawned processes cannot load modules defined during compilation
• [Keyword] Optimize Keyword.pop/3, Keyword.pop!/2, and Keyword.pop_lazy/3
• [List] Add List.to_existing_atom/2 and List.to_unsafe_atom/1
• [MapSet] Optimize MapSet.symmetric_difference/2 when set sizes differ
• [Path] Add Path.safe_join/2
• [Protocol] Add the :skip_consolidated option to Protocol.extract_protocols/2
• [Protocol] Warn when implementing a protocol for a module that does not define a struct
• [Registry] Add the :spawn_opt option to Registry.start_link/1
• [Registry] Optimize exact key matching in lookups
• [String] Optimize String.bag_distance/2
• [String] Add String.to_existing_atom/2 and String.to_unsafe_atom/1
• [URI] Optimize percent-decoding and URI.to_string/1

ExUnit

• [ExUnit.Assertions] Add trace/3 helper
• [ExUnit.CLIFormatter] Improve rendering of test locations in some terminals

Mix

• [mix test] Add --coverage-format to emit coverage reports as html (the default) or text

2. Bug fixes

Elixir

• [bin/elixirc] Fail compilation on warnings when --warnings-as-errors is given
• [Calendar] Fix Calendar.strftime/3 formatting of negative years with %y
• [Calendar] Fix rounding for :day, :hour, and :minute units in DateTime.diff/3, NaiveDateTime.diff/3, and Time.diff/3
• [Calendar.ISO] Fix Calendar.ISO.valid_time?/4 to reject non-integer microsecond precision
• [Calendar.ISO] Reject negative zero UTC offsets in basic formats
• [Code.Formatter] Fix rendering calls where do is followed by non-block keyword arguments
• [Code.Formatter] Keep comments written after do-end block keywords (such as rescue and after) or after the right side of an operator close to where they were written, instead of moving them before the whole expression
• [Code.Formatter] Keep parentheses on anonymous function calls with do-end blocks
• [Code.Formatter] Keep parentheses on unary operators on the left side of in, such as (!foo) in bar
• [Code.Fragment] Fix cursor completion when operator keywords such as in, when, and, or, and not follow another operator
• [Code.Fragment] Respect the :file, :line, and :column options in Code.Fragment.container_cursor_to_quoted/2
• [Date] Preserve the :format option in Date.to_iso8601/2 with custom calendars
• [Date.Range] Fix slicing date ranges with stepped ranges
• [DateTime] Keep the calendar of the given map in DateTime.convert/2 and DateTime.truncate/2
• [DateTime] Truncate fractional differences towards zero in DateTime.diff/3
• [Duration] Reject duplicate seconds in Duration.from_iso8601/1
• [DynamicSupervisor] Do not discard the exit reason of children that terminate during shutdown
• [Enum] Fix Enum.min/2,3 and Enum.max/2,3 with custom sorters on ranges
• [File] Trim UTF-32 LE BOMs in File.stream!/3
• [IO.ANSI.Docs] Do not crash on unclosed HTML comments
• [IO.ANSI.Docs] Recognize additional punctuation delimiters when rendering Markdown
• [Kernel] Continue compilation after reporting repeated map keys in patterns
• [Kernel] Do not consider local functions invoked in bitstring size expressions inside macros as unused
• [Kernel] Do not crash on invalid number specifiers in bitstrings inside functions
• [Kernel] Fix expansion of rebound variables in bitstring size expressions
• [Kernel] Expand defguard macros separately in guard and body contexts, preserving and/or error semantics outside guards
• [Kernel] Fix inferred stacktrace types to allow arbitrary keyword metadata
• [Kernel] Fix inferred types for functions with non-returning clauses
• [Kernel] Fix map field type inference in the presence of empty map types
• [Kernel] Fix tuple fetch and deletion type operations across equivalent tuple types
• [Kernel] Fix type checking of map updates with keys that span several domains
• [Kernel] Fix variables defined in one default argument leaking into subsequent default arguments
• [Kernel] Follow UAX #9 levels when computing the bidi skeleton of confusable identifiers
• [Kernel] Improve the error message for non-atom struct keys
• [Kernel] Raise when | is used in guards
• [Kernel] Raise on duplicate keys in @enforce_keys
• [Kernel] Fix parsing precedence of unary operators applied to do-end blocks, such as !if a do b end || c
• [Kernel] Do not accept empty tuples in elem/2 and other tuple operations during type checking
• [Kernel] Fix inferred types of comprehensions using :into with binaries and bitstrings
• [Kernel] Fix type checker crash on functions with impossible clauses
• [Kernel] Fix type checker crash on defimpl for modules that are not Elixir structs
• [Kernel] Fix unsound type refinement of min/2 and max/2 arguments
• [Kernel] Improve type precision of --/2
• [Kernel] Improve type precision of case when some of its clauses always raise
• [Kernel] Make pin patterns with singleton types precise, so subsequent redundant clauses are detected
• [Kernel] Report applying empty function types as bad functions instead of bad arities
• [Kernel] Support Erlang modules in import Mod, only: :sigils
• [Keyword] Delete duplicate keys when Keyword.get_and_update/3 and Keyword.get_and_update!/3 return :pop
• [Macro] Properly escape C1 control characters and Unicode noncharacters
• [Macro] Respect the disabled ANSI setting in Macro.dbg/3
• [Macro] Return true from Macro.quoted_literal?/1 for literals wrapped in __block__
• [Macro] Return valid AST from Macro.pipe/3 when piping into Access.get/3
• [NaiveDateTime] Fix NaiveDateTime.diff/3 over-counting incomplete units
• [OptionParser] Report missing and invalid arguments for switches with :keep
• [Range] Fix Range.disjoint?/2 for ranges beyond floating-point precision
• [Range] Fix Range.disjoint?/2 for single-element ranges with a negative step
• [Regex] Escape U+0085, U+200E, U+200F, U+2028, and U+2029 in Regex.escape/1, as Erlang/OTP 28+ ignores them in extended mode
• [String] Fix String.reverse/1 grapheme ordering around invalid UTF-8 bytes
• [String] Return 1.0 from String.bag_distance/2 for two empty strings
• [Time] Validate microseconds in Time.from_seconds_after_midnight/3

ExUnit

• [ExUnit.Assertions] Fix refute_in_delta/4 at the delta boundary and with negative deltas
• [ExUnit.Assertions] Support list literals in catch_throw/1, catch_exit/1, and catch_error/1
• [ExUnit.CaptureIO] Close the capture device when capture_io fails to set the group leader
• [ExUnit.CaptureIO] Stop StringIO processes when capturing a named device fails
• [ExUnit.CLIFormatter] Color the summary yellow only when all tests are excluded
• [ExUnit.CLIFormatter] Report failures whose messages contain invalid UTF-8
• [ExUnit.DocTest] Fix line numbers in doctest_file/2 failures
• [ExUnit.DocTest] Fix the expected line in doctests with multi-line expressions
• [ExUnit.FailuresManifest] Do not overlap failures of sibling parameterized tests
• [ExUnit.Filters] Warn on invalid line filters instead of raising in ExUnit.Filters.parse/1
• [ExUnit.Runner] Do not count excluded tests towards --max-failures on setup_all failures
• [ExUnit.Runner] Do not leak monitor messages when the test supervisor times out on shutdown
• [ExUnit.Runner] Give each parameter set of parameterized tests its own random seed
• [ExUnit.Runner] List tests in execution order with --dry-run
• [ExUnit.Runner] Preserve the order of async modules across --repeat-until-failure runs
• [ExUnit.Runner] Record tests invalidated by module failures as failures in the failures manifest

IEx

• [IEx.Autocomplete] Do not crash when the shell has no evaluator, such as while it restarts
• [IEx.Autocomplete] Fix completion crashes on maps with non-atom keys
• [IEx.Autocomplete] Do not split Unicode codepoints when completing map keys
• [IEx.Evaluator] Recognize ** and not in as continuation operators
• [IEx.Helpers] Do not crash process_info/1 on processes monitoring others by name
• [IEx.Helpers] Fix r/1 when multiple modules are defined in the same file
• [IEx.Helpers] Fix heap and stack memory calculations in process_info/1
• [IEx.Helpers] Fix showing macro specs in h/1
• [IEx.Helpers] Shell-quote file paths given to the editor in open/1

Logger

• [Logger] Restore the Erlang default handler when the :logger application stops
• [Logger.Backends] Do not remove the backends handler when formatting an event crashes, such as on a raising :report_cb
• [Logger.Backends] Support all handler configuration changes, such as :logger.set_handler_config/3, in the backends handler
• [Logger.Formatter] Prune surrogate code points in Logger.Formatter.prune/1

Mix

• [Mix] Ensure the lock and pubsub directories in the system tmp directory are owned by the current user
• [Mix.Generator] Support iodata contents in create_file/3 with :format_elixir
• [Mix.Rebar] Handle empty refs and charlist sparse directories in rebar Git dependencies
• [Mix.SCM.Git] Raise if Git refspecs start with -
• [mix cmd] Exit with the status of the failing command
• [mix compile] Compile optional dependencies that non-optional dependencies require when --no-optional-deps is given
• [mix compile.elixir] Recompile the project when --docs or --debug-info change
• [mix deps] Recompile path and fetchable dependencies when one of the dependencies they were compiled with is removed
• [mix deps] Mark fetchable dependencies for compilation when their build exists but their SCM manifest is missing
• [mix deps.compile] Preserve code paths and compiler options across OS partitions
• [mix escript.install] Respect the :path escript option and raise on URLs without a path
• [mix format] Invalidate the cached configuration when imported .formatter.exs files change
• [mix format] Pass :sigils to plugins invoked for sigils, allowing nested sigils to be formatted
• [mix local.hex] Install Hex with --if-missing when the installed version is older than the requested one
• [mix new] Avoid trailing whitespace in generated files
• [mix profile.tprof] Forward script arguments
• [mix release] Keep :erts in the release applications
• [mix test] Do not crash the coverage summary when there are no modules
• [mix test] Do not let the coverage threshold override the exit status of test failures

3. Hard deprecations

Elixir

• [Macro.Env] Macro.Env.fetch_alias/2 and Macro.Env.fetch_macro_alias/2 are deprecated, use Macro.Env.expand_alias/4 instead
• [Path] Path.safe_relative_to/2 is deprecated, use Path.safe_relative/2 instead

Mix

• [mix compile.elixir] --tracer is deprecated, set :tracers in :elixirc_options or use Code.put_compiler_option/2 instead

4. Soft deprecations

Elixir

• [IO.ANSI] blink_slow/0, conceal/0, crossed_out/0, cursor_left/0, cursor_right/0, home/0, no_underline/0, not_crossed_out/0, not_italic/0, not_overlined/0, overlined/0, reveal/0, reverse/0, and reverse_off/0 are deprecated in favor of the names aligned with Erlang/OTP
• [Kernel] Atom interpolation (:"foo_#{bar}") is deprecated in favor of explicit String.to_unsafe_atom/1
• [List] List.to_atom/1 is deprecated in favor of List.to_unsafe_atom/1
• [String] String.to_atom/1 is deprecated in favor of String.to_unsafe_atom/1

v1.20

The CHANGELOG for v1.20 releases can be found in the v1.20 branch.